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[mikefromMA]

Hey guys,

I did some research and couldn't find a definitive answer, so I'm asking the forces that be to help. I just had an alignment done on my 2011 M3 coupe with comp package at a reputable BMW dealership in Mass. As we all know, these are 19" wheels and the report states it was completed with an 18" wheel measurement. In regards to alignment, there was some discrepancies in the rear axle, but near zero discrepancies in the front. In addition, I was told the balance of each wheel was substantially off and needed at least 25-50 grams per.

Could the 18" measurement differentiate a balance vs. unbalance wheel or aligned vs. misaligned wheel? And if so, how much or how little should I care?

Thanks a lot, I really appreciate any responses.

[THE TECH]

Did you have something wrong that you needed an alignment?

[mikefromMA]

The car was pulling to the left, probably after a quarter mile I would drift into the opposite lane. Now I have vibrations and poor handling. It's miserable

[kornykidd0]

The vibrations are definitely due to balance. I just had AWFUL vibrations in my car...couple hours at the dealership being road force balanced cured it entirely. Car is a joy to drive again.

[mikefromMA]

So they balanced the tires and now it's a problem which was hardly noticeable...

[M3SQRD]

If they did use 18" as the reference diameter on your 19" wheels then, yes, that will have an effect on the wheel balance and/or the amount of balance weight required. The tire/wheel balance machine corrects for static and dynamic unbalance issues - the diameter is important because it defines the "plane separation".

Only you can answer your last question...do you still have wheel unbalance issues and/or steering wheel vibrations with the new balance weights? If the answer is "yes" then take your car back and have them perform the wheel balance correctly...

[paradocs98]

Originally Posted by M3SQRD

If they did use 18" as the reference diameter on your 19" wheels then, yes, that will have an effect on the wheel balance and/or the amount of balance weight required. The tire/wheel balance machine corrects for static and dynamic unbalance issues - the diameter is important because it defines the "plane separation".

Interesting info--there still is useful stuff on this board from time to time...

[mikefromMA]

Originally Posted by M3SQRD

If they did use 18" as the reference diameter on your 19" wheels then, yes, that will have an effect on the wheel balance and/or the amount of balance weight required. The tire/wheel balance machine corrects for static and dynamic unbalance issues - the diameter is important because it defines the "plane separation".

Only you can answer your last question...do you still have wheel unbalance issues and/or steering wheel vibrations with the new balance weights? If the answer is "yes" then take your car back and have them perform the wheel balance correctly...

awesome, thank you for the feedback. Turns out on second attempt, as you suggested, they determined the the alternative front wheel was slightly bent as well. I find it amazing that the car was given a good bill of health when there was still a noticeable issue with the vehicle. The rims have both since been replaced and the car is running perfectly. Nevertheless, I learned something regarding the alignment/balancing measurement...so for that